Project modernization (#630)

* Fixed boats falling and a TP glitch #266

* Replaced every C-style cast with C++ ones

* Replaced every C-style cast with C++ ones

* Fixed boats falling and a TP glitch #266

* Updated NULL to nullptr and fixing some type issues

* Modernized and fixed a few bugs

- Replaced most instances of `NULL` with `nullptr`.
- Replaced most `shared_ptr(new ...)` with `make_shared`.
- Removed the `nullptr` macro as it was interfering with the actual nullptr keyword in some instances.

* Fixing more conflicts

* Replace int loops with size_t and start work on overrides

Minecraft.World/StringTag.h

@@ -34,7 +34,7 @@ public:
 	{
 		if (Tag::equals(obj))
 		{
-			StringTag *o = (StringTag *) obj;
+			StringTag *o = static_cast<StringTag *>(obj);
 			return ((data.empty() && o->data.empty()) || (!data.empty() && data.compare(o->data) == 0));
 		}
 		return false;